U.S. patent application number 13/054796 was filed with the patent office on 2011-05-26 for method for operation of a dishwasher.
This patent application is currently assigned to BSH BOSCH UND SIEMENS HAUSGERATE GMBH. Invention is credited to Michael Fauth, Helmut Jerg, Kai Paintner, Andreas Reiter, Roland Rieger.
Application Number | 20110120501 13/054796 |
Document ID | / |
Family ID | 41279213 |
Filed Date | 2011-05-26 |
United States Patent
Application |
20110120501 |
Kind Code |
A1 |
Fauth; Michael ; et
al. |
May 26, 2011 |
METHOD FOR OPERATION OF A DISHWASHER
Abstract
A dishwasher and a method for operating a dishwasher, wherein a
liquid is heated at least twice with a first heater, and wherein
the first heater is an air heater.
Inventors: |
Fauth; Michael; (Pleinfeld,
DE) ; Jerg; Helmut; (Giengen, DE) ; Paintner;
Kai; (Adelsried, DE) ; Reiter; Andreas;
(Finningen, DE) ; Rieger; Roland; (Rainau,
DE) |
Assignee: |
BSH BOSCH UND SIEMENS HAUSGERATE
GMBH
Munich
DE
|
Family ID: |
41279213 |
Appl. No.: |
13/054796 |
Filed: |
July 28, 2009 |
PCT Filed: |
July 28, 2009 |
PCT NO: |
PCT/EP2009/059723 |
371 Date: |
January 19, 2011 |
Current U.S.
Class: |
134/25.2 ;
134/105 |
Current CPC
Class: |
A47L 15/4291 20130101;
Y02B 40/00 20130101; A47L 15/4285 20130101; Y02B 40/44 20130101;
A47L 15/481 20130101; A47L 15/4287 20130101 |
Class at
Publication: |
134/25.2 ;
134/105 |
International
Class: |
A47L 15/42 20060101
A47L015/42 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 28, 2008 |
DE |
10 2008 040 789.5 |
Nov 7, 2008 |
DE |
10 2008 043 550.3 |
Claims
1-24. (canceled)
25. A method for operating a dishwasher, the method comprising:
heating a liquid at least twice with a first heater, wherein the
first heater is an air heater.
26. The method of claim 25, wherein the dishwasher is a household
dishwasher.
27. The method of claim 25, wherein a water heater is used as a
second heater.
28. The method of claim 25, wherein, during the heating with the
air heater, a desorption of a reversibly dehydratable drying
material of a sorption drying system is at least partially
effected.
29. The method of claim 28, wherein the reversibly dehydratable
drying material is zeolite.
30. The method of claim 25, wherein a plurality of program steps is
run, and wherein the first heater is operated at least twice at
least temporarily during at least one of the plurality of program
steps.
31. The method of claim 25, wherein a plurality of program steps is
run, and wherein the first heater is operated at least temporarily
during at least two of the plurality of program steps.
32. The method of claim 27, wherein the second heater is only
operated at least temporarily during one of a plurality of program
steps.
33. The method of claim 31, wherein at least one at least partial
change in the liquid takes place between the at least two of the
plurality of program steps by means of pumping and refilling.
34. The method of claim 31, wherein a pre-rinsing with cleaning
action and without addition of detergent is implemented as a first
of the at least two of the plurality of program steps, and wherein
a cleaning with addition of the detergent and the cleaning action
is implemented as a second of the at least two of the plurality of
program steps.
35. The method of claim 31, wherein a cleaning with addition of
detergent and cleaning action is implemented as a first of the at
least two of the plurality of program steps, and wherein a rinsing
with addition of rinse-aid is implemented as a second of the at
least two of the plurality of program steps.
36. The method of claim 25, wherein the liquid is heated with the
first heater to a maximum temperature of essentially between
35.degree. C. to 50.degree. C.
37. The method of claim 36, wherein the maximum temperature is
between 40.degree. C. to 45.degree. C.
38. The method of claim 27, wherein the liquid is heated with the
second heater to a maximum temperature of essentially between
45.degree. C. to 80.degree. C.
39. The method of claim 38, wherein the maximum temperature is
between 55.degree. C. to 75.degree. C.
40. The method of claim 31, wherein a first operation period of the
first heater during a first of the at least two of the plurality of
program steps is 2 to 6 times as long as a second operation period
of the first heater during a second of the at least two of the
plurality of program steps.
41. The method of claim 40, wherein the first operation period of
the first heater is 3 to 4 times as long as the second operation
period of the first heater.
42. A dishwasher, comprising: a first heater to heat liquid at
least twice, wherein the first heater is an air heater.
43. The dishwasher of claim 42, wherein the dishwasher is a
household dishwasher.
44. The dishwasher of claim 42, further comprising a second heater,
wherein the second heater is a water heater.
45. The dishwasher of claim 42, further comprising a sorption
drying system that includes reversibly dehydratable drying
material, wherein the air heater is configured to effect at least
partially a desorption of the reversibly dehydratable drying
material during a heating process.
46. The dishwasher of claim 45, wherein the reversibly dehydratable
drying material is zeolite.
47. The dishwasher of claim 42, wherein the first heater is
configured to operate at least twice at least temporarily during at
least one of a plurality of program steps.
48. The dishwasher of claim 42, wherein the first heater is
configured to operate at least temporarily during at least two of a
plurality of program steps, and wherein the liquid is heated during
the at least two of the plurality of program steps.
49. The dishwasher of claim 44, wherein the second heater is only
operable at least temporarily during one of a plurality of program
steps.
50. The dishwasher of claim 48, wherein at least one at least
partial change in the liquid takes place between the at least two
of the plurality of program steps by means of pumping and
refilling.
51. The dishwasher of claim 48, wherein a first of the at least two
program steps is pre-rinsing with cleaning action and without
addition of detergent, and wherein a second of the at least two
program steps is cleaning with addition of the detergent and
cleaning action.
52. The dishwasher of claim 48, wherein a first of the at least two
program steps is cleaning with addition of detergent and cleaning
action, and wherein a second of the at least two program steps is
rinsing with addition of rinse-aid.
53. The dishwasher of claim 48, wherein the first heater is
configured to heat the liquid to a maximum temperature of
essentially between 35.degree. C. to 50.degree. C.
54. The dishwasher of claim 53, wherein the maximum temperature is
between 40.degree. C. to 45.degree. C.
55. The dishwasher of claim 44, wherein the second heater is
configured to heat liquid to a maximum temperature of essentially
between 45.degree. C. to 80.degree. C.
56. The dishwasher of claim 55, wherein the maximum temperature is
between 55.degree. C. to 75.degree. C.
57. The dishwasher of claim 47, wherein the first heater is
configured to operate during a first operation period during the
first of a plurality of program steps that is 2 to 6 times as long
as a second operation period of the first heater during a second of
the plurality of program steps.
58. The dishwasher of claim 57, wherein the first operation period
is 3 to 4 times as long as the second operation period.
Description
[0001] The invention relates to a method for operation of a
dishwasher, in particular a household dishwasher, according to the
preamble of claim 1.
[0002] Dishwashers are known, which run wash programs comprising a
plurality of program steps, like for instance, pre-rinsing,
cleaning, intermediate rinsing, rinsing with rinse-aid and drying
of the cleaned items to be washed. In this way, during some of the
program steps, like for instance the pre-rinsing or cleaning,
liquid is heated with a heating means embodied as a flow-through
water heater, with this possibly being the same amount of liquid
which is heated twice with the flow-through water heater, or two
amounts of liquid. The heating process with a flow-through water
heater provides for a quick heating of the liquid, which
nevertheless exposes sensitive items to be washed to particular
loads.
[0003] The object underlying the invention is to reduce the thermal
loads in particular of sensitive items to be washed.
[0004] The invention is based on a method for operating a
dishwasher, in particular a household dishwasher, in which liquid
is heated at least twice with a first heating means.
[0005] In accordance with the invention, provision is made for an
air heater (HZ) to be used as a first heating means. The air heater
is therefore operated at least twice during a wash program in order
to effect a heating of one or two amounts of liquid. This allows
for a heating process which is gentle on the items to be
washed.
[0006] In a development, provision is made for a water heater to be
used as the second heating means. This provides for a further,
quicker heating process without extending the wash program
duration.
[0007] In a development, provision is made for a desorption of a
reversibly dehydrogenizeable drying material, in particular
zeolite, to be effected at least partially during the heating
process with the air heater. The desorption thus takes place in two
phases, which are separated from one another for instance by means
of a complete or partial change in liquid by means of pumping and
refilling. A complete desorption of the drying material is then
also ensured if the duration of a first program step is not
sufficient to achieve a complete desorption.
[0008] Provision is made in a development for the method to run a
plurality of program steps, with the first heating means being
operating at least temporarily during at least two program
steps.
[0009] Provision is also made in a development for the second
heating means to only be operated at least temporarily during a
program step. A particularly energy-efficient operation of the
dishwasher is thus possible.
[0010] Provision is made here in a development for at least one at
least temporary change in liquid to take place between the at least
two program steps by means of pumping and refilling.
[0011] Provision is also made in a development for a pre-rinsing
with cleaning action without the addition of detergent to be
implemented as a first program step and a cleaning with the
addition of detergent and cleaning action to be implemented as a
second program step. This provides for a particularly intensive
cleaning of the items to be washed, since heated liquid is already
applied to the items to be washed during the pre-rinsing program
step.
[0012] In a development, provision is made for a cleaning with the
addition of detergent and detergent action to be implemented as a
first program step and a rinsing with the addition of rinse-aid to
be implemented as a second program step. This effects a
particularly good drying of the items to be washed, since prior to
the drying program step, heated liquid is applied to the items to
be washed during the rinsing with rinse-aid program step.
[0013] In a development, provision is made for liquid to be heated
with the first heating means to up to a maximum temperature of
essentially between 35 to 50.degree. C., in particular between 40
to 45.degree. C. Once these temperatures have been reached, an
improved cleaning action can be achieved during a pre-rinsing
program step and/or an improvement in the drying performance can be
achieved during a drying program step.
[0014] In a development, provision is made for liquid to be heated
with the second heating means to a maximum temperature of
essentially between 45 to 80.degree. C., preferably 55 to
75.degree. C. An essentially complete desorption of the drying
material is thus ensured.
[0015] Provision is made here in a development for the period of
operation of the first heating means during the first program step
to be 2 to 6, preferably 3 to 4 times as long as during the second
program step.
[0016] The object of the invention is also achieved by a
dishwasher, in particular a household dishwasher, having a first
heating means, with which liquid can be heated at least twice, with
provision being made in accordance with the invention for the first
heating means to be embodied as an air heater.
[0017] Developments of the inventive dishwasher are specified in
the subclaims.
[0018] The invention and its development are described in more
detail below with the aid of drawings, in which;
[0019] FIG. 1 shows a schematic representation of an exemplary
embodiment of an inventive dishwasher having a sorption drying
system,
[0020] FIG. 2 shows a schematic representation of the temperature
gradation during a first exemplary embodiment of an inventive wash
program cycle,
[0021] FIG. 3 shows a schematic representation of the temperature
gradation of a further, second exemplary embodiment of an inventive
wash program cycle, and
[0022] FIG. 4 shows a schematic representation of the temperature
gradation of a further, third exemplary embodiment of an inventive
wash program cycle.
[0023] Reference is firstly made to FIG. 1.
[0024] A dishwasher GS embodied in the present exemplary embodiment
as a household dishwasher comprises an interior IR which is used as
a wash tub, it being possible to open and close said interior for
loading and unloading purposes by means of a door (not shown) which
is pivotably hinged to the dishwasher GS. Racks GK for receiving
items to be washed are provided in the interior IR of the
dishwasher GS, it being possible to remove said racks from the
interior IR of the dishwasher GS in order to facilitate the loading
and unloading processes.
[0025] To clean the items to be washed which are stored in the
racks GK, provision is made for means, which are embodied in the
interior IR of the dishwasher GS as spray arms SA, for applying
liquid to the items to be washed, with it being possible for the
liquid to be water mixed with detergent or rinse-aid for instance
in order thus to bring about a cleaning action and/or streak-free
drying process. The liquid discharged from the items to be washed
collects in a sump PS, which is arranged in the bottom region of
the interior IR of the dishwasher GS.
[0026] The spray arms SA are connected in a liquid-conducting
manner to a circulating pump UP by way of a feed pipe ZL, said
circulating pump UP being arranged adjacent to other components of
the dishwasher GS in a bottom module BO below the interior IR of
the dishwasher GS. During operation, i.e. with a functioning
circulating pump UP, the circulating pump UP draws in the liquid
accumulating in the sump PS and transports this through the feed
pipe ZL to the spray arms SA. In order to heat the liquid which is
circulated during operation of the circulating pump UP, the
circulating pump comprises an integrated water heater WZ for
heating the liquid. Alternatively, in addition to the circulating
pump UP, a separate flow-through water heater or another water
heater can be provided. A drain pump LP is provided to empty the
interior IR of the dishwasher GS, said drain pump likewise being
connected in a liquid-conducting manner to the sump PS and possibly
being connected to a domestic waste water disposal network using a
waste disposal line EL.
[0027] The dishwasher GS also comprises a sorption drying system,
with which items to be washed which are cleaned and arranged in the
racks GR can be dried at the end of a wash program cycle. To this
end, a sorption container SB is provided in the bottom module BO,
said sorption container being connected in an air-conducting manner
to an inlet EI via an air duct LK, with a fan LT being provided to
generate a forced flow. A blow-out opening AU is provided in the
bottom region of the interior IR of the dishwasher G in order to
transport the air drawn-in through the inlet El and routed into the
sorption container through the fan LT back into the interior IR of
the dishwasher GS.
[0028] To effect a drying of the cleaned items to be washed, air is
drawn out of the interior IR of the dishwasher GS by means of the
fan LT, routed through the sorption container SB and back into the
interior IR of the dishwasher GS through the blow-out opening AU.
In order herewith to dry the air circulated, a drying means is
provided in the sorption container SB in order to implement an
exothermic drying process. This is a reversibly dehydronizeable
drying material, e.g. zeolite, which, as a result of its
hydroscopic property, absorbs water, with thermal energy being
released at the same time. This released thermal energy heats the
circulated air, which at the same time increases the moisture
absorption ability of the circulated air. An amount of liquid is
stored in the drying material ZEO at the end of a drying
process.
[0029] An air heater HZ is provided in order to reproduce the
absorption ability of the drying means ZEO for a renewed wash
program cycle, said air heater, in the present exemplary
embodiment, being arranged in the sorption container SB. It is
however also possible to arrange an air heater outside of the
sorption container SB, e.g. in the air duct LK, in order to heat
the air conveyed into the sorption container SB. To expel the
amount of liquid stored in the drying material ZEO, an air flow
generated with the fan LT is heated so that the drying material ZEO
can be heated to temperatures at which the amount of water stored
in the drying material ZEO can be released again.
[0030] Reference is now also made to FIGS. 2 to 4.
[0031] Dishwashers GS run wash programs for cleaning and drying
items to be washed, said wash programs consisting of a plurality of
program steps which are run one after the other. A program of this
type can consist of the program steps pre-rinsing V, cleaning R,
intermediate rinsing Z, rinsing with rinse-aid K and drying T, with
it also being possible for individual program steps, like for
instance the pre-rinsing V or intermediate rinsing Z, to be faded
out, while it is also conceivable to run individual program steps
repeatedly, like for instance the intermediate rinsing Z. During
the pre-rinsing V, water is applied to the items to be washed for
instance without the addition of detergent, with this either being
implemented with unheated water or with water heated by means of a
heater. To this end, water that was stored in a water tank (not
shown) can be used. A water tank of this type can be connected in a
heat-conducting manner to the surroundings of the dishwasher, so
that liquid stored intermediately in the water tank, like for
instance water from a domestic supply system, can heat up to room
temperature. In the cleaning step R, the items to be washed are
cleaned by applying water mixed with detergent, i.e. the addition
of detergent is effected during the cleaning step. Furthermore, the
liquid is heated in order thus to increase the cleaning action of
the detergent. Here the cleaning step R is composed of a heating
phase P1, P2, in which the liquid in the dishwasher GS is heated by
means of heating means, until a predetermined maximum temperature
is reached and a subsequent post-wash phase, during which the
slowly cooling liquid is circulated by means of the circulating
pump UP when the heating means is switched off. In the intermediate
rinsing program step Z, liquid is applied to the items to be washed
in order thus to transport dirt residues out of the dishwasher GS.
The next program step is the rinsing with rinse-aid K for preparing
the drying program step T, in which water mixed with rinse-aid is
circulated by means of the circulating pump and is applied to the
now cleaned items to be washed by way of the spray arms SA. The
drying program step T then takes place, in which liquid is no
longer applied to the items to be washed, but an air flow
circulating through the interior IR of the dishwasher GS and the
sorption container SB is instead generated by operating the fan LT.
A complete or at least partial exchange of liquid can be
implemented between the individual program steps, i.e. the
dishwasher GS is emptied by means of the drain pump LP and the
waste disposal line EL and is refilled again by a supply line (not
shown) which establishes a connection with a domestic supply
system.
[0032] With the wash program cycle according to FIG. 2, liquid is
only heated in the cleaning program step R. Here during a first
phase P1, starting from a start temperature T0, the liquid
circulated with the circulating pump IP is initially heated by the
air heater HZ in the sorption container SB to a maximum temperature
T1, with the fan LT simultaneously generating an air flow which
circulates through the interior IR of the dishwasher GS. The air
heater HZ heats the drying material ZEO in the sorption container
SB to temperatures at which the amount of water stored in the
drying material ZEO is expelled out of the drying material ZEO and
is transported in the interior IR of the dishwasher GS through the
blow-out opening AU. The effect of the air heater HZ heats this
amount of liquid and thus effects a heating of the total amount of
liquid in the interior IR of the dishwasher GS by mixing the liquid
already circulated with the circulating pump UP. As a result of a
heating up to the first temperature T1 taking place by means of the
air heater HZ during the cleaning program step R, it is ensured
that the drying material ZEO can be reliably and completely
desorbed from the interior IR of the dishwasher GS by circulating
relatively cold and dry air. Instead of a rigid wash program cycle,
during which a desorption process is implemented in a first program
section, in which liquid is heated, provision can also be made in
an alternative exemplary embodiment to evaluate the parameters
influencing the desorption process in order to determine the point
in time at which the desorption is implemented. This may be the air
temperature and the water inflow temperature. For instance, a
desorption process can take place in a cleaning or rinsing with
rinse-aid program step or also, if expedient, during the
pre-rinsing program step.
[0033] During the desorption process, the air heater HZ cools the
blow-out opening AU in the interior IR of the dishwasher GS in
order thus to ensure that no excessive heating of the blow-out
opening HZ with overheating damage results due to the heating
output of the air heater HZ.
[0034] To this end, the circulating pump UP is operated during the
operation of the air heater HZ, i.e. during the phase P1 for
instance, so that liquid is transported by the circulating pump
from the sump PS through the feed pipe to the spray arm SA. The
spray arms SA are herewith made to rotate and by spraying the
blow-out opening AU, in particular a casing covering the blow-out
opening AU, with liquid, effect a cooling of the same.
[0035] In a next phase P2 of the cleaning program step R, the
amount of liquid is heated by means of the water heater WZ starting
from the first temperature T1 to the second temperature T2.
[0036] To increase the cleaning action during the cleaning program
step R, provision is made to increase the spray pressure of the
water jets originating from the spray arm SA by increasing the
speed of the circulating pump UP. To this end, during the cleaning
program step R, during the post-wash phase NA, the amount of liquid
circulated by means of the circulating pump UP is increased by a
post-filling step, for instance at point in time t1 (cf FIG. 2) and
the speed of the circulating pump UP is then increased, e.g.
continuously until the circulating pump proceeds again
rotationally, i.e. does not draw in any air bubbles during
operation, which reduces the delivery rate of the circulating pump
UP and results in the development of unwanted noise. It is herewith
possible to take the amount of liquid released during the
desorption process, which was stored in the drying material ZEO,
into account when assessing the amount of liquid to be filled and
thus to reduce the overall water requirement with an improved
cleaning capacity.
[0037] A drip phase AB is provided between the rinsing with
rinse-aid program step K and the drying program step T (cf. FIG.
2), while the liquid adhering to the cleaned items to be washed,
i.e. water mixed with rinse-aid, can drain off from the items to be
washed due to gravity and can collect in the sump PS of the
interior IR of the dishwasher GS. The amount of liquid to be
absorbed by the sorption drying system is herewith reduced and
therefore the duration of the drying program step T.
[0038] A pumping process, during which the liquid mixed with
rinse-aid is routed through the waste disposal line EL into a
domestic waste water disposal system by means of the drain pump LP,
takes place prior to this drip phase AB, i.e. at the end of the
rinsing with rinse-aid program step K. The drip phase AB follows,
during which neither the circulating pump UP nor the drain pump LP
and nor the fan LT nor one of the cited heaters HZ, WZ are in
operation. Upon completion of this drip phase AB, the drying
program step T begins by commissioning the fan LT, so that an air
flow circulating through the interior IR of the dishwasher and the
sorption container SB is generated in order to dry the cleaned
items to be washed in the racks GK. At the end of the drying
program step T, a further pumping process takes place by means of
the drain pump LP, by means of which a remaining amount of liquid
is transported out of the dishwasher GS through the waste disposal
line EL into a domestic waste water disposal system. Alternatively,
to this end provision can also be made to implement a further
pumping process in addition or alternatively to starting the drying
program step T.
[0039] With the wash program according to FIGS. 3 and 4, liquid is
heated in the first of the program steps, the pre-rinsing program
step V. To this end, during a phase P1', liquid is heated starting
from a start temperature T0 to a temperature T1' by means of the
air heater HZ, at which temperature T1', as described above, an air
flow circulating through the interior IR of the dishwasher GS and
the sorption container SB is generated by means of the fan LT.
After reaching the temperature T1', the air heater HZ is
deactivated. At this point in time, the drying material ZEO is
still not completely desorbed, i.e. a residual amount of water is
stored in the drying material ZEO. To expel this residual amount of
water from the drying material ZEO and thus to have a completely
water-absorbable drying material ZEO available again at the start
of the drying program step T, in the subsequent cleaning program
step R the liquid is firstly heated to a temperature T1 by means of
the aid heater HZ and is then heated to the temperature T2 by
operating the water heater. In other words, the desorption phase of
the drying means ZEO in the sorption container SB is divided in
this exemplary embodiment and arranged into two program steps,
namely the pre-rinsing program step V and the cleaning program step
R.
[0040] To increase the cleaning action by further increasing the
temperature, a further phase P3 (cf. FIG. 3) can be provided,
during which a further heating of the liquid to a temperature T3
takes place with the water heater WZ.
[0041] To improve the drying result at the end of the drying
program step T, provision is made in the exemplary embodiments
according to FIGS. 3 and 4 for liquid to be heated during the
rinsing with rinse-aid program step K. To this end, during a phase
P4, liquid, which is either water or water mixed with rinse-aid, is
heated to a temperature T4 by means of the water heater WZ.
Alternatively the air heater HZ can also be used instead of the
water heater, in order for instance to achieve a desorption which
was previously incomplete in the program cycle. In addition, during
a further phase P5, the liquid can be further heated to a
temperature T5 in order to improve the drying with the sorption
drying system.
LIST OF REFERENCE CHARACTERS
[0042] AB drip phase [0043] AU blow-out opening [0044] BO bottom
module [0045] El inlet [0046] EL waste disposal line [0047] GK rack
[0048] GS dishwasher [0049] HZ air heater [0050] IR interior [0051]
LK air duct [0052] LP drain pump [0053] LT fan [0054] NA post-wash
phase [0055] P1' phase 1' [0056] P1 phase 1 [0057] P2 phase 2
[0058] P3 phase 3 [0059] P4 phase 4 [0060] P5 phase 5 [0061] PS
sump [0062] SA spray arm [0063] SB sorption container [0064] t1
post-fill point in time [0065] T0 start temperature [0066] T1'
temperature [0067] T1 temperature [0068] T2 temperature [0069] T3
temperature [0070] T4 temperature [0071] T5 temperature [0072] UP
circulating pump [0073] WZ water heater [0074] ZEO drying material
[0075] ZL feed pipe
* * * * *